Chapter 24: On the definition of philosophy

1. Philosophy is the knowledge of things human and divine, united with a zeal for right living. It seems to consist of two things, knowledge and opinion.

2. It is knowledge when anything is known with definiteness; opinion, when a thing lurks as yet in uncertainty and seems in no way established, as for example, whether the sun is [only] as large as it seems or greater than all the earth; likewise whether the moon is a sphere or concave; and whether the stars adhere to the heavens or pass in free course through the air; of what size the heaven itself is and of what material it is composed; whether it is quiet and motionless or revolves with incredible speed; how great is the thickness of the earth, or on what foundations it continues poised and supported.

3. The word philosophy, translated into Latin, means _amor sapientiae_. For the Greeks call amor φιλὸν, and sapientiae σοφίαν. The sub-division of philosophy is three-fold: first, natural philosophy, which in Greek is called _physica_, in which there is discussion of the search into nature; the second, moral, which in Greek is called _ethica_, in which the subject is morals; the third, rational, which in the Greek is called _logica_, in which the discussion is as to how the truth itself is to be sought in respect to the causes of things or the conduct of life.

4. In physics, then, the cause of inquiry, in ethics, the manner of living, in logic, the method of understanding, are concerned. Among the Greeks, Thales of Miletus, one of the seven wise men, was the first to search into natural philosophy. For this man first regarded with contemplative thought the causes of the heavens and the force of the things of nature. And this division of philosophy Plato afterward divided into four separate parts, namely, into arithmetic, geometry, music, astronomy.

5. Socrates first established ethics with a view to correcting and ordering conduct, and he devoted all his attention to the discussion of right living, dividing it into the four virtues of the soul, namely, wisdom, justice, fortitude, temperance.

6. Wisdom is engaged with things, and by it the evil is distinguished from the good. Fortitude, by which adversity is endured with calmness. Temperance, by which lust and concupiscence are bridled. Justice, by which through righteous judgment his own is rendered to each.

7. Plato added logical philosophy, which is called rational, and by it he analyzed the causes of things and of conduct, and examined their force in a rational way, dividing it into dialectic and rhetoric. It is called logical, that is, rational, for among the Greeks λόγος means both word and reason.

8. The divine utterances also consist of these three kinds of philosophy. For they are wont to discuss nature, as in Genesis or Ecclesiastes; or conduct, as in Proverbs and here and there in all the books; or logic, instead of which our [philosophers] assert the claim of theology,[232] as in the Song of Songs or the Gospels.

[232] Du Breul has _theologia_; Arevalus, _theorica_.

9. Likewise some of the teachers have defined philosophy in its name and parts as follows: “Philosophy is the probable knowledge of divine and human affairs, as far as is possible for man.” Otherwise: “Philosophy is the art of arts and the science of sciences.” Again: “Philosophy is the meditation upon death, a definition which better suits the Christians, who trampling on worldly ambition, live in the intercourse of learning after the likeness of their future country.”

10. Others have defined the scheme of philosophy as made up of two parts, of which the former is contemplative, the latter practical. The contemplative (_inspectiva_) is divided into natural, theoretical, and divine. Theoretical is divided into four parts, into arithmetic, music, geometry, and astronomy.

11. Practical (_actualis_) philosophy is divided into moral, economic, and civil. Contemplative is the name given that in which, passing beyond the visible, we enjoy some contemplation of the divine and celestial, and behold them with the mind alone, since they pass beyond the bodily gaze.

12. Natural philosophy is the name given when the nature of each and every thing is discussed, since nothing arises contrary to nature in life, but each thing is assigned to those uses for which it was purposed by the Creator, unless perchance by God’s will it is shown that some miracle appears.

13. It is called divine philosophy when we discuss the ineffable nature of God or the spiritual beings that are in some degree of a lofty nature.

14. The science which considers abstract quantity is called theoretical. For that is called abstract quantity which we separate from the material, or from other accidents, by the intellect, and treat by reasoning alone, as _e.g._, equal, unequal, and other matters of this kind....

16. Further, that is called practical philosophy which by its workings makes problems clear, of which there are three parts, moral, economic, and civil. That is called moral by which an honorable custom (_mos_) of living is sought and practices tending to virtue are established. That is called economic (_dispensativa_) in which the order of domestic affairs is wisely arranged. That is called civil by which the advantage of a whole state is secured.